Many studies have documented important racial disparities in surgical outcomes but their etiologies are not clear. While we generally find better surgical outcomes (lower mortality) at teaching hospitals, and a higher rate of minority patients at these hospitals, the survival benefit at teaching hospitals does not seem to equally apply to white and black patients. This application will explore why we observe disparities in three common surgical specialties that are performed throughout most hospitals where surgery is practiced: general, orthopedic, and vascular surgery. The application will focus on a classic measure of surgical practice - the procedure time. While always available on chart review, the ability to study surgical procedure time on a vast scale with Medicare claims is new. Anesthesiologists began billing Medicare by the minute in 1994. Using these bills to estimate procedure length in a population of Pennsylvania patients, we have recently published that there was a significant and clinically important disparity in the length of operations based on race and income, after detailed adjustment for patient characteristics and procedure type. This disparity was greatest at hospitals with residency programs, where the procedure time of black patients in the lowest third of the income distribution was on average 31 minutes longer than that of white patients at the same level of income (P<0.0001). In non-resident hospitals the mean gap was 8 minutes (P<0.0001). In further work we have shown that the disparity in procedure length gets larger with longer procedure times (at the 95 percentile using quantile regression, the difference between blacks and whites is about 3 of an hour). Furthermore, in our examination of all teaching and non-teaching hospitals in the state of Pennsylvania, the 15 hospitals with the largest number of black patients undergoing orthopedic and general surgery, excess adjusted procedure time (black-white by hospital) was statistically significant in 5 of 15 hospitals, with their mean excess times ranging from 9 to 16 minutes. The strength of using operative time as a measure of disparity is that it reflects precisely what the surgical and anesthesia team have done, and is not confounded by patient compliance or preferences, as some other measures of process and outcome may be. This application aims: (1) To study and describe racial and income/SES disparity in procedure time across surgeons and hospitals;(2) To identify the determinants of disparity in procedure time across surgeons and hospitals. We will study those geographic, hospital, and surgeon characteristics associated with the greatest disparities in procedure time;and (3) To make practical recommendations to departments of surgery regarding procedure length and to create models to allow surgery departments to practically monitor such disparities in order to develop mechanisms to eliminate problems if found.